**Discussion Group on Self-Gravitational Instability:**
It has been suggested (Gibson, 1996) that the Jeans
criterion for self-gravitational condensation is inadequate and
generally misleading as a guide to structure formation in
cosmology and astrophysics. Rather than condensing on
acoustic nuclei at the Jeans scale, condensation occurs on
any nucleus at scales determined by turbulence or viscous
forces (if a sticking mechanism exists). This view leads to
earlier, much smaller scale, condensations for baryonic
matter and later, much larger scale, condensations for
weakly interacting "WIMPs" than usually anticipated (e.g.,
Padmanabhan, 1994).

By the proposed scenario, condensation begins at
viscous-gravitational scales during the plasma epoch for
baryonic matter at 10^47 kg to 10^42 kg masses. Upon
plasma neutralization the inviscid, non-turbulent gas
promptly condenses to particles at about 10^22 kg within
foam-like nested structures (galaxies, clusters, superclusters)
partially formed previously. These moon-mass "primordial
fog" particles (PFPs) of hydrogen-helium should thus be the
source material for all subsequent structures. The first stars
should be formed gently, at small masses, by gradual
accretion of PFPs. Remaining PFPs should be quite cold
and compact by now, and may constitute most of the
baryonic dark matter of galactic halos. Some PFPs have
possibly been recently revealed (by Hubble Space Telescope
photographs) as cometary globules in planetary nebulae.
WIMP fluid should increase the viscosity, entropy, and
homogeneity of the universe, but condense slowly and at the
largest scales to form galaxy cluster and super cluster halos.

Recent deep field HST photographs show galaxies of
stars existed at 750,000 years following the big bang, and
possibly much earlier. The first stars to form should have
been blue, massive and short lived (as in spiral galaxy arms)
by the Jeans criterion, and red, small and long lived (as in
globular clusters) by the primordial fog scenario. The oldest
HST deep field galaxies appear to be red, not blue.

Can the traditional structure formation scenarios be
modified to explain the recent data? Does data exist that can
test the primordial fog particle scenario? Are there any
theoretical difficulties? Are there theoretical alternatives?
Such questions could be aired in the proposed discussion
group.